Push button electric switch



Oct. 5, 1937. H. A. DOUGLAS 2,095,179

PUSH BUTTON ELECTRIC SWITCH Filed May 51, 1934 45 at? U lNl/E/VTOR 45 IVA/FRY A. DOUGPLHS ra ak w M IYIIA Patented Oct 5, 1931 UNITED STATES PATENT OFFICE-W I 2,095,119 rnsn nu'rron EIECTRIC swrrcn Harry A. Douglas, Bronson,- Mich, assignor to Kingston Products Corporation, a corpora- I tion of Indiana Application May 31, 1934, Serial No. 128.284

' 1 Claims. (Cl. 200-159) this invention with'the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawing Figure 1 is a view in central vertical section of an embodiment of this invention, with parts illustrated in elevation.

Figure 2 is a similar view in section taken at right angles to Figure 1.

Figure 3is a view similar to Figure 1, illustrating the position of the circuit making and breaking mechanism just before onecircuit is broken, with parts broken away.

Figure 4 is a detail view in section taken on the line 4-4, Figure 3.

As illustrated in Figures 1, 2, and 3, the switch- .ing mechanism is enclosed in a cup-shaped metallic cylindrical casing I having the bottom or end closure 2 provided with a central circular opening 3 for the reception of a shouldered push button 4 of insulating material having a flange 5 upon the.bottom thereof to engage the inner side of the closure 2 to prevent the button 4 from passing therethrough, as shown. The under side of the button is provided with a diametrlcal groove 8 fora purpose hereinafter described. The open end of the casing I is closed by a contact carrying disc I of insulating material which is held securely in position by a plurality 40 of spaced-apart fingers 8, preferably. three in number, forming integral extensions of the casing wall which are passed through corresponding notches 9 in the periphery of the disc I and then bent back over the outer surface of the disc to hold' the same firmly against the end of the casing wall. The contact carrying disc I mounts two electric terminals I0 and I I, preferably of the snap terminaltype disclosed in this applicants prior copending application, Serial No. 713,713, filed March 2, 1934, adapted to be electrically connected to electric conductors, not shown, upon the outer side of the disc I. As shown, each terminal includes a rectangular block having a cylindrical extension. which extensions are preferably reduced in diameter. when thistype terminal I0 is spaced apart from the contact I5 and minal is employed, it is desirable to provide the carrier disc 'I with circular apertures through which the reduced extremities of the terminals are passed and the metal of the end is then expanded or riveted upon the interior of the disc I to hold the terminals in place. The terminals III and II are mounted on perpendicular radii of the disc I an equal distance from the center.

The center of the contact carrying disc I is provided with an integral rectangular projection of insulating material I upon its inner surface having sides I! parallel to the radii passing through the terminals Ill and II with the edge adjacent terminal Ill joined to an upwardly extending angular surface l3 terminating in a central transverse fiat portion ll. An'electric contact It in the form of a metallic strip is con nected to terminal l0, preferably by passing the reduced cylindrical portion thereof through an aperture provided therefor in the end of said strip, upon the outer side of the contact carrying disc. The other end of the strip is then passed through the disc I to embrace the adjacent side and angular surface l3 of the central projection I with the upper surface of the strip flush with the flat top ll of the central projection I. The upper surface of the insulating projection leading from the flat top of the transverse portion l4 opposite the contact strip I5 is continued downwardly therefrom at an angle similar to that formed by the upper surface of said strip for a similar distance and then curved upwardly to form' a stop I6. for a purpose hereinafter described.v The expanded or riveted head of the terminal III is preferably received in a recess 5 provided therefor upon the inner surface of the disc I to be wholly received below that surface, for a purpose hereinafter described.

The switching mechanism is carried upon a U- shaped ,metallic bracket having a rectangular base II with a central cut out portion I8, toreceive the projection I of the disc I, providing end portions I0, one of which extends over the countersunk expanded end of the terminal Ill and having the sides of the base I! provided with integral outstanding perforated ears"!!! and 2|. The reduced cylindrical portion of the terminal is passed through the apertured' ear 2!] with the end expanded or riveted upon the upper surface thereof while, the other ear 2i is'secured to the disc I by a rivet 22 passing through the ear and disc with the metal of the ends expanded or riveted thereon. Thetinner sideof the end. portions IQ of the base extending over the terthe opposite end portion l 9 is in engagement with the central projection I of the disc 1. The spaced apart'end portion 19 is provided upon its inner side with an integral upwardly extending stop 23 bent back at an angle and spaced apart from the contact 15 to form a stop complementary to the stop 16 of the projection I.

The ear bearing sides of the base are extended upward to form two similar arms 24 perpendicular to the base l1 and equally spaced from the axis of the casing I with each side of each arm provided midway its height with outstanding integral fingers 25. The switching device for alternately continuing the circuit from the terminal II to the contact I5 of the terminal I0 is mounted to oscillate upon a pivot 26 passing through apertures in the upper ends of the arms 24. The circuit making and breaking mechanism includes an oscillating actuator A caused to oscillate by an oscillating operator 0.

The actuator A is mounted upon a pivot pin 26 passed through apertures in the arms 24 of the supporting bracket and includes two similar metallic actuating plates 21 adapted to receive the pivot pin 26 and depend therefrom in sliding engagement with the respective arms 24 of the supporting bracket and terminating short of. the high point of the carrier disc projection I with a portion of the opposite longitudinal sides struck up at right angles to the main body to form right angular flanges 28 extending upward from the bottom leaving oppositely disposed similar outstanding arms 29 extending from the body of the plate, the longitudinal edges of the flanges 28 are adapted to engage the similar edges of the corresponding flanges on the respective plates 21. The actuator plates 21 are mounted upon the pivot pin 26 in similar longitudinally elongated bearings 30 allowing a sliding longitudinal movement of the plates about the pin 26. The upper surfaces of the actuator arms 29 lie in the same plane which passes slightly below the axis 7 of the pivot pin 26 when the upper end of the bearing 30 is in contact with the upper surface of the pin 26. A spring housing 3| in the form of an inverted U is mounted between the plates 21 and embraced by the flanges 28, the extremities of the sides of the housing are provided with transverse flanges 32 adapted to pass under'the lower extremities of the actuator flanges 29 with the terminations thereof inclined upwardly to engage the outer sides of the oppositely disposed actuator. flanges on each side of the housing and position the base or top of the housing at a distance below the lower end of the actuator bearmounted on the disc 1, from riding over either of the stops 16 or 23.

The actuator A carrying this current continuing bridge 34 is caused to oscillate by the movement of an oscillating operator 0. The oscillating operator 0 is preferably formed of a flat strip of metal centrally struck up to form oppositely disposed similar angular flat surfaces 36 departing downwardly from its transverse center line terminating in upwardly extending tangential stops 31 with the opposite sides struck downwardly to form depending perforated ears 38 adapted to be received between the actuator plates 21 and receive the pivot pin 26 and mount the operator for oscillation thereabout below the meeting edge of the surfaces 36 parallel with and in the same plane as the axis of the pivot and with the upper surfaces of the actuator arms 29 in contact with the under surfaces of the tangential stops 31 when the lower end of the bearings 39 of the actuator are in engagement with the under side of the pivot pin 26. When the bridge nose, actuator and operator have been assembled upon the supporting bracket, the fingers 25 of the bracket arms 24 are bent toward each other, as shown in Figure 2, to prevent the nose 34 when mounted on the disc 1 from riding over either of the stops 16 or 23.

Back and forth movement is imparted to the oscillating operator 0 by the manual movement of a roller 39 mounted to travel in the diametrical groove 6 upon the under side of the button 4.

The roller 39 is rotatably mounted upon a resilient member, preferably a coil spring 40, passing axially therethrough and at right angles to the groove 6 with its opposite ends secured to a bracket carried by and reciprocable with the button 4. The top 4| of the bracket is received in recesses in the bottom of the button 4 perpendicular to the groove 6 with its under surface flush with the under surface of the button and centrally offset at 43 to follow the contour of the under'surface of the button as it passes over the groove 6 preferably provided with upstanding angular portions 44. anchored in the body of the button 4. The top 4| of the bracket extends beyond the button with each extending side 45 brought back on the arc of a circle to join two parallel arms 46 depending parallel to and equidistant from the casing axis the lower ends of which are each provided with central longitudinal slots 46a adapted to receive and travel over extensions 41 of the actuator and oscillating operator pivot pin 26. The upper portions of the sides 45 of the curved ends of the bracket are preferably struck down to provide anchors 49 for the ends of the spring 40 and the lower ends 49 of the bracket sides 46 are preferably bent outwardly, as shown in Figure 2, so that the slots 46 therein may receive-the extensions 41 of the pivot 26 without continuing said slots through the lower edge of the said sides. It is also preferable to provide the bore 50 of the roller 39 with Walls that flare outward from the center for a purpose hereinafter described;

As shown in Figure 1, the roller 39 and the flange 5 of the button 4 are so proportioned that after a circuit has been closed through contact I 5 the roller engages the angular surface 36 of the operator on the same side as the closed contact which engagement is adjacent the high point of the meeting edge of the angular surface 36 with the upper side of the flange 5 spaced apart from the under side of the casing closure 2, and the axis of the spring 40 is astraight line between its anchors 48. Upon a depression of the button 4, the roller 39 is caused to travel over'the contiguous angular surface 36 of the operator guided in the groove 6 acting as a track therecontinued depression of the button I, the roller 39 imparts a rotative movement to the oscillating operator and through the contact of the engaged stop 31 with the adjacent actuator arm 29 first bodily moves the actuator in the direction of the engaged stop 23 of. the bridge nose 34 until the upper end of the bearing 30 engages the upper side of the pin 26, placing the detent spring 35 under greater tension than normal. As the button 4 continues downward, its movement is transmitted through the roller 39 to impart a rotative movement to the actuator A about its upper hearing on the pivot 26 causing the detent nose 34 to travel over the upwardly inclined surface of the contact I5 towards its high point, as shown in Figure 3, holding the contact with the terminal Ill closed under a slightly increasing tension of the spring 35 as the nose approaches the high point of the contact. During this rotative movement the pivot pin 26 acts as the fulcrum of a bell crank lever with the power being applied upon one arm by the roller 39at the point of contact P between the oscillating operatorend 31, and the actuator arm 29. Duringthis movement, the point of contact P moves in the direcpoint, the spring 35 bodily moves the actuator upward and awayirom the contact to bring the lower end of its bearing 39 into engagement with the under side of the pin 25 with the nose 34still held in contact with the strip i5, and during this movement'causes the actuator to rotate nose 34 to snap over the high point of the contact about the point P as a pivot. r In other words,

during the application of power at P, the bell crank lever rotates about the pivot 25 as a fulcrum, but as the nose 34 approaches the high point of the contact l5, power is applied at the lower end of the other arm of the bell crank lever causing it to rotate about the point P as a fulcrum, the elongated bearing 39 allowing sliding movement of the actuatorabout the flxed pivot 26. The movement imparted to the actuator by the stored up power of the spring 35 causes the I5 and to quickly extend the nose 3! toengage the stop I6 on the other end of the projection I and thereby quickly oscillate the bridge to break engagement with the contact of the terminal III.

From the above, it'is seen that as soon as the spring carried roller 39 has rotated the oscillating operator sufliciently to shift the actuator from its normal pivot 26 to its eccentric pivot P, the spring 35 automatically. completes the oscillation -to snap the nose out of engagementwith the contact strip l5 and thereby break the circuit from t'erminal Ii to terminal l0. Upon release of the button 4, the tension of the spring 40 causes the roller 39 to travel upward over the angular surface. 36 from the stop 31 the roller has just rotated and pass over the high point of the actuator to assume the position ,shown in Fig ure 1 and in so doing lifts the button 4 until its flange 5 engages the inner surface of the casing closure 2 so that after passing over the high point the flange 5 assumes its normal spaced apart relation to the casing closure. The opposite sides of the oscillating operator 0, oscillating actuator A and projection I being similar, upon the next depressionof the button, the spring carried roller 39 will engage the side of theoscillating operator thereunder to impart rotative movement to the actuator from its normal to its eccentric pivot and snaps the bridge nose to close the circuit.

As shown and described, the parts of this improved switchingmechanism excepting the push button and contact carrier are all adapted to be formed of metal stamping to be easily and quickly assembled. The operating parts are dependable as the spring 35 for imparting the snap movement is fully protected, and the other parts are so constructed that the switch may be operated thousands of times without any of the parts deteriorating or getting out of order. This construction provides for the oscillation of the operator by the depression of the push button contacting the roller 39 in engagement with the operator forming a very compact switching mechanism. Certain features, common to the present application and to applicants Patent 2,044,065,

June 16, 1936, are claimed in the aforesaid patent.

What I claim is:

1. An electric switch including a casing, acontact carrier mounted therein, switching mechanism mounted on the carrier within the casing including a plurality of spaced apart contacts, a current continuing bridge mounted for oscillation and adapted to make and break alternately a circuit from one contact to another upon oscillation, an actuator mounted for oscillation about a pivot, an oscillating operator mounted on the actuator pivot having means to engage and oscillate the actuator, said actuator having a s1iding engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement with its pivot and with said bridge, means guided by the actuator pivot extending through the casing for manual reciprocation to oscillate the operator to engage and move the actuator over its pivot and rotate the actuator to travel in sliding engagement with the bridge, said means includinga spring disposed transversely of the oscillating operator.

2. The structure of claim 1 wherein the manually operable means includes a reciprocable frame for mounting said spring.

' 3. The structure of claim 1 wherein the manmlly operable means includes a reciprocable frame for mounting said spring and wherein said spring is a coil spring having its ends anchored to said frame.

4. The structure of. claim 1 wherein the manually operable means includes a reciprocable frame for mounting said spring, wherein said spring is a coil spring having its ends anchored to said frame, and wherein a push button mounted for reciprocation in the casing wall is carried I upon said frame.

5. An electric switch including a cup-shaped casing, a contact carrier mounted upon the open end thereof, a switching mechanism mounted onthe contact carrier including a plurality of spaced apart contacts, a metallic bracket electrically connected to one of said contacts, a current continuing bridge mounted foroscillation adapted to make and break alternately a circuit through oscillating operator mountedupon the actuator 'pivothav'ing means to e ge and oscillate the actuator, said actuator having a sliding'engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement with its pivot and with said bridge, means mounted upon thebracket extending through the casing for manual reciprocation to oscillate the operator to engage and move the actuator over its pivot and rotate the actuator to travel in sliding engagement with the bridge,

and means to shift the axis of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to make or break a circuit from one contact to another contact, said manually operable means including a roller to engage and travel over said oscillating operator upon reciprocation of said means.

6. An electric switch including a casing, a contact carrier mounted therein, switching mechanism mounted on the carrier within the casing including a plurality of spaced apart contacts, a current continuing bridge mounted for oscillation and adapted to make and break a circuit alternately from one contact to another upon oscillation, an actuator mounted for oscillation about a pivot, an oscillating operator mounted on the actuator pivot having oppositely disposed downwardly extending angular surfaces forming a stop at the lower end and forming means to engage and oscillate the actuator, said actuator having a sliding engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement with its pivot and with said bridge, means guided by the actuator pivot extending through the casing for manual reciprocation alternately engaging the respective angular surfaces of the operator to oscillate the operator to engage and move the actuator over.its pivot and rotate the actuator to travel in sliding engagement with the bridge, and means to shift the axis of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to make or break the said circuit, said manually reciprocable means including a frame with a push button mounted thereon for reciprocation in the casing wall said frame coacting with the actuator pivot to guide said frame upon reciprocation.

'7. An electric switch including a casing, a contact carrier mounted therein, switching mechanism mounted on the carrier within the casing including a plurality of spaced apart contacts, a current continuing bridge mounted for oscillation and adapted to make and break a circuit alternately from one contact to another upon oscillation, an actuator mounted for oscillation about a pivot, an oscillating operator mounted on the actuator pivot having oppositely disposed downwardly extendingangular surfaces forming astop at the lower end and forming means to engage and oscillate the actuator, said actuator having a sliding engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement 'with its pivot and with said bridge, means guided by the actuator pivot extending through the casing for manual reciprocation alternately engaging the respective angular surfaces of the operator to oscillate the operator to engage and move the actuator over its pivot and rotate the actuator to travel in sliding engagement with the bridge, and means to shift the axis of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to make or break the said circuit, the manually operable means including a frame having two parallel slotted depending arms to embrace the actuator pivot and a push button mounted for reciprocation in the casing wall carried upon the upper side thereof with a coil spring stretched between said arms and adapted upon depression of the button to travel over an angular surface of the operator and engage the stop therein placing the spring under greater tension which tension upon release of the push button returns the frame to normal extended position.

8. An electric switch including a casing, a contact carrier mounted therein, switching mechanism mounted on the carrier within the casing including a plurality of spaced apart contacts, a current continuing bridge mounted for oscillation and adapted to make and break a circuit alternately from one contact to another upon oscillation, an actuator mounted for oscillation about a pivot, an oscillating operator mounted on the actuator pivot having oppositely disposed downwardly extending angular surfaces forming a stop at the lower end and forming means to engage and oscillate the actuator, said actuator having a sliding engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement with its pivot and with said bridge, means guided by the actua tor pivot extending through the casing for manual reciprocation alternately engaging the respective angular surfaces of the operator to oscillate the operator to engage and move the actuator over its pivot and rotate the actuator to travel in sliding engagement with the bridge, and means to shift the axis of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to make or break the said circuit, the manually operable means including a frame having two parallel slotted depending arms to embracethe actuator pivot and a push button mounted for reciprocation in the casing wall carried upon the upper side thereof with a coil spring stretched between said arms and adapted upon depression of the button to travel over an angular surface of the operator and engage the stop therein placing the spring under greater tension which tension upon release of the push button returns the frame'to normal extended position and a roller mounted upon said spring to bear upon the said angular surface.

9. An electric switch including a casing, a contact carrier mounted therein, switching mechanism mounted on the carrier within the casing including a plurality of' spaced apart contacts, a current continuing bridge mounted or oscillation and adapted to make and break a circuit alternately from one contact to another upon oscillation, an actuator mounted for oscillation about a pivot, an oscillating operator mounted on the actuator pivot having oppositely disposed downwardly extending angular surfaces forming a stop at the lower end and forming means to engage and oscillate the actuator, said actuator having a sliding engagement with its pivot and sliding engagement with the bridge, means maintaining the actuator in engagement with its pivot and with said bridge, means guided by the actuator pivot extending through the casing for manual reciprocation alternately engaging the respective angular surfaces of the operator to oscillate the operator to engage and move the actuator over its pivot androtate the actuator to travel in sliding engagement with the bridge, and means to shift the axis of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to make or side thereof with a coil spring stretched between said armsand adapted upon depression ofthe button to travel over an angular surface of the operator and engage the stop therein placing the spring under greater tension which tension upon release of the push button returns the frame to normal extended position and a roller mounted upon said spring to bear upon the said angular surface and travel in a groove provided upon the under side of the push button '-to maintain its alignment with said surface upon reciprocation of the button.

10. An electric switch, comprising: a base; contacts carried by said base; a pivot structure, carried by said base; and providing a pivot;

means swingable aboutsaid pivot, including a circuit continuing portion movable to open or close a circuit between said contacts, and a portion having surfaces on opposite sides of said \pivot and angularly disposed with respect to each other; an operating member, mounted formovement from one position to another; and spring means, interposed between said operating member and said angularly disposed surfaces, and having its ends secured to said operating member and its axis normally in a plane including the axis of said pivot, said spring means and said angularly disposed surfaces being so constructed and arranged thatwhen said operating means Y is moved from one positionto said other position,

said spring means, intermediate its ends, will flex from normal position and move relatively to one of said surfaces so as to move said swingable means about said pivot.

11. An electric switch, comprising: a base; contacts carried by said base; a pivot structure, carried by said base; and providing a-pivot; means swingable about said pivot, including a circuit continuingyportion movable to open or close a circuit between said contacts, and a portion hav ing surfaces on opposite sides of said pivot, and angularly disposed with ,respect to each other; an operating member, mounted for movement from one position to another; and spring-means, interposed between said operating member and said angularly disposed surfaces, and having its ends secured to said operating member and its axis normally in a plane including the, axis of said pivot, said spring means and said angularly disposed surfaces being so constructed and arranged that when said operating means is moved from said one position to said other position, said spring means, intermediate its ends, will flex from normal position and move relatively to one of said surfaces so as to move said swingable means about said pivot, said-spring means urging said operating member to return to said one position, so that said spring means may assume its normal position, and in such normal position, said spring means will be of said angularly disposed surfaces, to move said swingable means in an opposite direction.

12. An electric switch, comprising: abase; contacts carried by said base; a pivot structure, carried by said base, and providing a pivot; means swingable about said pivot, including a circuit continuing portion movable to open or close a circuit between said contacts, and a portion having operating parts on opposite sides ofsaid pivot; an operating member, mounted for movement disposed in line to engage the other from one position to another: and spring means. interposed between said operating member and said operating parts, and having its ends secured to said operating member, and its axis normally ina plane including the axis of said pivot; said operating parts and said operating member beingso constructed and arranged that movement 'of said' operating member from said one position to said other position will'flex the intermediate portion of said spring means from normal position relatively to one of said operating parts, and move said operating parts so as to move said swingable means about said pivot, said spring means being put under tension during such movement of said operating member, and the tensional force of said spring reacting against said engaged operating part and said operating member to urge said operating member to return to said one position so that said spring may assume its normal position.

13. An electric switch,'comprising: a base; contacts carried by said base; a pivot structure, carsaid spring normally maintaining said interposed means in central position; said interposed means being so constructed and arranged that when said operating means is moved from said one position to said other position, said roller will engage one of said operating parts, and move said operating parts to thereby move said swingable means about saidpivot, said operating parts being so constructed and arranged that during movement of said operating member said spring and roller mechanism alsowill be moved generally at right angles to the movement of said operating member.

14. An electric switch, comprising: a base; a pivot structure, carried by said base and providing a pivot; switch actuating means swingable about said pivot and including an operating surface; operating means mounted for movement from one position to another and including rasilient means supported at its ends and disposed in the general direction of the axis of said pivot; and said operating means and said operating surface being relatively so constructed and arranged that when said resilient,

means is moved toward said operating surface force is applied to said resilient means to flex it transversely oi. its length and cause said surfaces on opposite sides of said pivot; operat-' ing means mounted for movement from one position to another and including resilient means supported at its ends and disposed in the general direction of the axis of said pivot; and said operating means and-said operating surfaces being relatively so constructed and arranged that when said resilient means is moved toward either 16. An electric switch. comprising: a base; a pivot structure, carried by said base and providing a pivot; switch actuating means swingable about said pivot and includingan operating surface; operating means, mounted for movement from a normal position to an operating position, so constructed and arranged that when in said normal position it rests on said operating surface; said operating means including resilient means; and'said operating'means and said operating surface being relatively so constructed and arranged that when said operating means is moved toward said operating surface force is applied to said resilient means to store energy therein and to cause said switch actuating means to swing about said pivot and so that when said operating means is released said operating means is returned to its normal position and the energy for so returning it is sup plied solely by said stored energy.

17. An electric switch, comprising: a base; a pivot structure, carried by said base and providing a pivot; switch actuating means swingable about said pivot and including an operating surface; operating means mounted for movement from one position to anotherand' including resilient means supported at its ends and disposed in the general direction of the axis of said pivot, and including also a roller disposed about said resilient means, and means for guiding said roller for movement in a direction transverse to said axis; and said operating means. and said operating surface being relatively so constructed and arranged that when said resilient means is moved toward said operating surface force is applied to said resilient means, through the intermediation of said roller, to flex it transversely of its length and cause said switch actuating means to swing about said pivot.

18. An electric switch, comprising: a base; a pivot structure, carried by said base and providing a pivot; switch actuating means swingable about said pivot and including an operating surface; operating means, mounted for movement from a normal position to an operating position, so constructed and arranged that when in said normal position it rests on said operating surface; said operating means including resilient means supported at its ends and disposed in the general direction of the axis of said pivot; and said operating means and said operating surface being relatively so constructed and arranged that when said operating means is moved toward said operating surface force is applied to said resilient means to flex it transversely of its length and to cause said switch actuating means to swing about said pivot and so that when said operating means is released said operating means is returned to its normal position solely by reason of the flexed condition of said resilient means.

HARRY A. DOUGLAS. 

